Method and means of sheet imbricating and stacking

ABSTRACT

A method and means of sheet imbricating and stacking of flexible sheets, such as signatures processed and delivered by a folder. A conveyor receives the sheets from the folder and delivers the sheets to another conveyor which moves at a speed less than the speed of the first conveyor. The slow moving conveyor deposits the sheets on a bed where the sheets are aligned in a stack. The first conveyor supports the sheets from underneath, and the first conveyor has a projection which holds the sheets upwardly relative to the remainder of the conveyor so that clearance is provided between the sheets and the remainder of the conveyor. Also, a brush is disposed adjacent the conveyor for brushing the trailing edge of the sheets upwardly. The projection and the brush are for the purpose of providing a space between the sheets and the remainder of the conveyor so that the oncoming sheets can be disposed underneath the sheets already on the first conveyor, and the sheets can therefore be taken from a spaced-apart relationship as they approach the first conveyor and then placed in an imbricated relationship on the first conveyor. The first conveyor then passes the imbricated related sheets to the second conveyor, and the sheets can then be stripped directly off the second conveyor and formed into a stack.

United States Patent Stobb [451 Apr. 4, 1972 [54] METHOD AND MEANS OF SHEET I IMBRICATING AND STACKING 71 Ansrmcr Primary Examiner-Joseph Wegbreit Assistant Examiner-Bruce H. Stoner, Jr. Attorney-Arthur J. Hansmann A method and means of sheet imbricating and stacking of flexible sheets, such as signatures processed and delivered by a folder. A conveyor receives the sheets from the folder and delivers the sheets to another conveyor which moves at a speed less than the speed of the first conveyor. The slow moving conveyor deposits the sheets on a bed where the sheets are aligned in a stack. The first conveyor supports the sheets from underneath, and the first conveyor has a projection which holds the sheets upwardly relative to the remainder of the conveyor so that clearance is provided between the sheets and the remainder of the conveyor. Also, a brush is disposed adjacent the conveyor for brushing the trailing edge of the sheets upwardly. The projection and the brush are for the purpose of providing a space between the sheets and the remainder of the conveyor so that the oncoming sheets can be disposed underneath the sheets already on the first conveyor, and the sheets can therefore be taken from a spaced-apart relationship as they approach the first conveyor and then placed in an imbricated relationship on the first conveyor. The first conveyor then passes the imbricated related sheets to the second conveyor, and the sheets can then be stripped directly off the second conveyor and formed into a stack.

8 Claims, 3 Drawing Figures PATENTED AFR 4 I972 SHEET 1 OF 2 I NI/E N TOR: AN TON R. 5 708B 21 T TORNE) METHOD AND MEANS OF SHEET IMBRICATING AND STACKING This invention relates to a method and means of sheet imbricating and stacking. More particularly, it relates to the handling of printed sheets or the like, such as folded signatures being prepared for books and magazines and being processed and delivered by a sheet folder.

BACKGROUND OF THE INVENTION The prior art is already aware of methods and various means for folding sheets into signature form, and then delivering the sheets through a system of conveyors and to a stacker to where the sheets are collected in a stacked arrangement. Examples of such prior art are found in my U.S. Pats. Nos. 2,841,394 and 3,188,082, both of which disclose the conveyance of an imbricated stream of sheets wherein the sheets are stripped from the stream and are directly stacked on a bed or in a stacker box. Where the sheets are folded into signature form, then they are processed by a folder and then stacked. If they are not folded, then they might come directly from a printing press and be placed onto conveyors and moved to the stacker. In all instances, the sheets are placed in imbricated or echeloned relationship of being overlapped, as shown in the present disclosure and also as shown in the two cited patents. With the sheets being over-lapped, then the sheets can be stripped directly from the over-lapped stream and the sheets are then positioned in a stack on a collector bed or the like.

In the method and means of imbricating the stream and stripping the sheets from the stream to form the stack, it is efficient and desirable that the leading edges of the sheets be against the conveyor which is in direct flow communication with the bed or collector for the stack. With that relationship, the sheets can then be stripped directly off the imbricated stream and the sheets are then positioned directly onto the bed. This orientation of the imbricated stream and location of the bed relative to the imbrication orientation are shown in my U.S. Pat. No. 3,188,082. In that patent, the sheets being deposited onto the first conveyor are dropped onto the conveyor and then moved upwardly and back toward their original position, so that the orientation of the imbrication and the location of the collector'bed are properly related for the stripping action described.

In the present invention, the sheets are separately and individually taken from a folder or the like, and the sheets are moved in a spaced-apart or separated stream relationship, rather than having the sheets overlapped or imbricated at this point. The separated sheets are then moved to a conveyor which handles the sheets in a manner so that the sheets can be placed in the desired imbrication relationship. To do this, the sheets are lifted on the second conveyor, and the sheets are also moved at a slower speed on the second conveyor relative to the speed of the sheets coming from the folder or the like. Because of the sheets being lifted and moved slower, they can be positioned in the desired imbricated relation so that the sheets can then be stripped from the imbricated stream and placed directly into a stacker.

In the art of sheet handling, broadly as described above, it is already known to provide method and means for conveying the sheets initially at a fast speed and ultimately conveying the sheets at a slower speed. It is also already known in the art that the slowing down of the sheets permits the positioning of the sheets in an imbricated stream relationship. One example of this prior art is shown in British Pat. No. 343,345, issued Feb. 19, 1931. However, this British patent differs from the present disclosure in several significant respects, including the fact that the imbricated stream is in a different relationship to the supporting conveyor, compared to the present invention, and the stream is also in a different relationship relative to the gripper cylinder shown in the British patent, compared to the present invention. These and other differences will become apparent upon reading the respective disclosures.

Accordingly, it is an object of the present invention to provide an efficient and high speed method and means for stacking signatures, all in a manner that permits the stacking to be done directly from the folder or like gripper cylinder handling the signatures in separated relationship prior to the imbricated stream relationship of the sheets or signatures.

It is a more, specific object of this invention to provide a method and means of sheet conveying and stacking, wherein the result is a simplified handling of the sheets, in that extended conveyors and means for directing the stream of sheets into different orientation, are not required. That is, the method and means of the present invention are simplified, require much less floor space and mechanism, and are less expensive and highlyreliable in the operation.

Another object of this invention, and confirming the aforementioned objects, it is significant that the method and means of this invention provide the handling of sheets'directly from a folder and placing them immediately into a collector box in a BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view of a preferred embodiment of this invention.

FIG. 2 is a developed or diagramatic plan view of the conveyor system shown in FIG. 1.

FIG..3 is a sectional view of parts shown in FIGS. 1 and 2, and with the view being taken substantially on the line 3-3 of FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A delivery cylinder 10 is rotatably mounted on a shaft 11 and carries gripper fingers 12 which pivot toward and away from the circumference 13 of the cylinder 10, all in a conventional manner. A folded signature 14 is shown gripped by the gripper 12, and it will be understood that the signature 14 has been passed from a cylinder 16 which may be a sheet folder cylinder, all in a conventional manner, suchas shown in FIG. 1 of U.S. Pat. No. 2,435,881. The cylinder '10 rotates in the direction of the arrow A, and it therefore has a conveyor belt 17 trained thereover and trained over a pulley 18 located on a shaft 19. Thus the belt 17 is disposed underneath the signature l4, and it moves the signature 14 against the conveyor disposed above the cylinder 10 and shown by a belt 21 which is suitably mounted for movement in the direction of the arrow B. Belt 21 is rotatably mounted on a pulley 22 and guided over pulley or cylinder 23 to extend between the pulleys 22 and 23, as shown. Also, a belt 24 is trained on the cylinder 10 to the side of the belt 17, and the belt 24 is also trained on a pulley 26 mounted on a shaft 27', as further described hereinafter. Thus the belts l7 and 24 move at a linear speed identical to the speed of the circumference of the cylinder 10, and belt 24 is a timing belt to assure that pulley 26 has its circumference 28 moving at a linear speed identical to the linear speed of the circumference 13 of cylinder 10, for a purpose hereinafter mentioned.

A conveyor belt 29 is also trained on the pulley 26 and on the cylindrical type pulley 18.

Thus, the signatures 14 are passed between the conveyors l7 and 21 and onto the conveyor 29, with the latter operating at the same linear speed of the conveyor 17.

Finally, a conveyor 31 receives the signatures 14 and places them into the stack 32 supported on a bed or stacker 33. Thus the conveyor 31 is supported between the cylindrical type pulley 34 and the pulley 36 keyed to the shaft 27 for rotation therewith. It will also be noted that the drawing shows the circumference 37 of the pulley 36 is larger than the circumference 38 of the pulley 26, for a purpose described hereinafter.

With the arrangement described, the signatures 14 are then conveyed along the sections of the conveyor, as described, and, when the signatures 14 reach the conveyor 31, they are placed into the imbricated relationship shown above the pulley 36, and such relationship is achieved by lifting the signatures 14 with respect to the conveyor 29 and by operating the conveyor 31 at a linear or surface speed slower than that of the upstream conveyors, namely conveyors 29 and 17. Because of the imbricated relationship shown, the signatures 14 can therefore be taken directly from a folder, or the like, and moved in a separated stream or individually and then moved into the imbricated stream, from whence the signatures are directly stripped off the imbricated stream on the conveyor 31 and are placed into the stacked relationship at 32.

. Such operation requires that the signature leading edges, such as the edge designated 38 on the one signature 14 shown on the top portion of the conveyor 31, be in contact with the conveyor 31, while the trailing edge 39 of the preceeding signature, as shown immediately above the pulley 36 in FIG. 1, be on the side of the imbricated stream away from contact with the conveyor 31 which leads the signatures into the stacker 33. With this imbrication orientation of the signature leading edgesbeing in contact with the conveyor 31, the signatures can then be stripped directly off the conveyor 31 and placed in the stacked relationship 32. In moving the signatures as described, the conveyor 29 moves in the direction of the arrows designated C, and the conveyor 31 extends adjacent and moves in the directions of the three arrows designated D.

FIG. 2 shows a developed view of one possible arrangement of the conveyor belts described. Here it will be again seen that conveyor belts 17 move the sheets to a relationship of sheetflow communication with the conveyor belts 29 which in turn is in sheet-flow communication with the conveyor belts 31. Thus the conveyor section 31 is disposed downstream, relative to the sheet-flow, and the conveyor section 39 is disposed upstream, as is the conveyor section 17.

While the conveyors 17 and 29 are moving at the same linear speed, the conveyor 31 is moving at a slower speed to effect the imbrication described. Thus, when the signatures 14 arrive at the conveyor 31, the leading edges 38 are retarded in their forward motion in the direction of the stream of sheets, but the conveyor 29 continues to bring the sheets onto the conveyor 31 at the higher speed to thereby provide the desired imbrication as described and shown. Further, in order to provide the imbrication in the proper orientation, that is with the sheet leading edges 38 in contact with the conveyor 31, the oncoming sheets or signatures 14 are disposed underneath the sheets or signatures already on the conveyor 29. To accomplish this, a projection 41 is provided on the conveyor 29 and it presents an upstanding wall or abutment 42 to the leading edges of the signatures 14. The projection 41 is affixed to the conveyor belts 29, and one such projection 41 is shown on the belt 29 so that one complete cycle of the belt 29 presents the projection 41 in the position shown in FIG. 1. The projection 41 causes the signatures 14 to be lifted on the conveyor 29, and a brush 43 is rotatably mounted on a shaft 44 and is disposed above the conveyor 29 to engage the sheet trailing edges 39 as they pass under the brush 43. The brush rotates in the direction of the arrow E, and thus the sheet trailing edges 39 are lifted relative to the conveyor 29 and therefore the oncoming signature 14 is permitted to be slid under the previous signature 14 and against the abutment 42 or at least adjacent to it. Therefore the sheets or signatures 14 are imbricated.

When the projection 41 moves to its position on the pulley 26, the projection 41 is no longer in contact with the signatures 14 for the purpose of moving the signatures 14, since the circumference 28 of the pulley 26 is recessed relative to the circumference 37 of the pulley 36 on which the belt 31 is trained. Therefore, the belt 31 now takes over the control of movement of the signatures, and only the belt 31 does so and it does so at the slower speed so the sheets are imbricated as described and shown.

FIG. 3 shows the timing lugs or teeth 46 on the belt 24 and it shows the lugs 47 on the belt 29, and it also shows the teeth or lugs 48 on the pulley 26, and such pulley is actually an idler pulley mounted on the rotatably mounted shaft 27 so that the belts 24 and 29 are moving at the same linear speed, as mentioned.

FIG. 3 also shows that the belt 31 has timing teeth or lugs 49, and the pulley 36 has timing teeth 51 so the belt 31 and pulley 36 will have the same linear speed. FIG. 2 shows a driving motor 52 operatively connected to the shaft 27 for rotating the latter and driving the pulleys 36. FIG. 3 shows that the pulley 36 has a key 53 for rotating the pulley 36 with the drive of the shaft 27, all at the slower speed desired.

Having imbricated the sheets as described and shown, a stripper bar 64 extends along a portion of the belts 31 to cause the signatures 14 to be stripped from their imbricated stream and stacked in the stack 32. Also, a presser belt 56 is suitably mounted and disposed above the imbricated stream as it enters the box or stack 32, and the belt 56 is suitably mounted by the pulleys 57 and 58, as shown. Also, a brush 59 is rotatably mounted to brush the signature trailing edges 39 to the left as viewed in FIG. 1, and thereby provide entry for the incoming imbricated stream of signatures 14, so the brush 59 rotates in a clockwise direction, as viewed in FIG. 1.

A roller 61 is rotatably mounted adjacent the roller or cylinder 23 to receive the signatures between the rollers 23 and 61 and thereby press the signatures as they move between the two rollers 23 and 61. The roller 23 is pivotally mounted on a pivot shaft 62 which supports a bell-crank 63 which in turn is influenced by a control arm 64 having a spring 66 applied thereto. Thus the bell-crank 63 is spring urged to have the roller 23 pressed downwardly and press the passing signatures l4 and thereby insure their folds. Also, the brush 43 has its shaft 44 mounted on an arm 67 which is pivotally supported on a shaft 68. The arm 67 also connects to an adjusting block 69 to which a threaded arm 71 is extended. Thus rotation of the arm 71 by means of the adjusting handle 72 will pivot the arm 67 about the shaft 68 and it will thereby adjust the horizontal or lateral position of the brush 43. By this means, the brush 43 can be adjusted so that it is positioned to accurately engage the signature trailing edges 39. Further, the adjustment of the brush 43 provides an adjustment for different lengths of signatures 14. Also, it will be understood that the different lengths of signatures 14 would provide a different height for the stack 42, and, to accommodate the different height, the brush 59 would then also be adjustable, and such adjustment would be in the vertical direction.

The belt 21 is extended over the pulley 23 and continues on to the cylinder for brush 43, as shown in FIG. 1. Thus when the brush 43 is adjusted, the tension for belt 21 is also accommodated by means of a pivotal arm 72 mounted on a shaft 73. In this arrangement, tension can then be maintained in belt 21 when brush 43 is adjusted and the adjustment carries with it the shaft 44 on which pulleys may be mounted for the belt 21, as is evident in FIG. 1.

It will therefore be understood that signatures are moved to the abutment 42, and the conveyor 29 moves the signature leading edges at the fast speed until the leading edges come under control of the conveyor 31, at which time the belt 29 becomes inactive on the signatures. The result is that the signatures are tucked under each other to cause the imbrication.

I claim:

1. In a sheet stacker of the type including a conveyor for upwardly supporting and moving sheets in a stream relation, a bed in sheet-flow communication with said conveyor for receiving said sheets from said conveyor and collecting said sheets in a stacked relation, the improvement comprising said conveyor including a downstream section disposed in advance of and in sheet-flow communication with said bed for feeding said sheets toward said bed, said conveyor including an upstream section disposed in advance of said downstream section relative to the flow of said sheets for feeding said sheets to said downstream section, the two said sections being disposed in overlapping relation for transferring said sheets from said upstream section to said downstream section and in said stream relation, drive means operative on said sections for driving said sections at two different speeds and with the speed of said downstream section being slower than the speed of said upstream section to cause said sheets to overlap on said downstream section, and lifter means including a raised portion on said upstream section and operative on said sheets on said upstream section to lift said sheets upwardly relative to said upstream section to provide clearance for the oncoming ones of said sheets to move underneath said sheets already on said upstream section and thereby have said sheets overlap on said upstream section.

2, The sheet stacker as claimed in claim 1, wherein said lifter means for overlapping said sheets includes a brush rotatably mounted above said upstream section for engaging the trailing edges of said sheets in the stream and raising said trailing edges off said upstream section for providing clearance for movement of the leading edges of said sheets underneath each respective leading one of said sheets in the stream.

3. The sheet stacker as claimed in claim 1, wherein said conveyor includes a first section in sheet-flow communication with said upstream section, and including a drive connection operative on said first section for driving said first section at the speed of said upstream section and with said raised portion being located along the length of said upstream section to present said raised portion adjacent the leading edges of said sheets coming onto said upstream section.

4. The sheet stacker as claimed in claim 1, wherein said downstream section and said upstream section respectively include rotatable members disposed on a common axis, and with said rotatable member of said upstream section and said raised portion being of a combined radial extent no greater than that of said rotatable member of said downstream section for conveying the oncoming ones of said sheets underneath those of said sheets on said downstream section.

5. A sheet stacker for a method of stacking sheets, comprising first conveyor means for conveying sheets in a stream relation and at a first speed and separated from each other, second conveyor means in sheet-flow communication with said first conveyor means for receiving said sheets therefrom and for conveying said sheets at a second speed slower than said first speed, means for driving said first conveyor means and said second conveyor means at their respective said speeds, lifter means operative on said sheets for singly lifting each of said sheets and positioning the following one of said sheets underneath each lifted one of said sheets to provide an imbricated stream of said sheets, and stacker means for stacking said sheets by stripping said sheets off said imbricated stream on the side of said imbricated stream to which said sheets were lifted.

6. A method of imbricating and stacking sheets being conveyed in an edgewise and stream relation by a conveyor moving at a first speed and with said sheets separated from each other, comprising the steps of conveying said separated sheets at a second speed which is slower than said first speed and in a direction having a horizontal component of motion, lifting the trailing edges of said sheets at a speed according to said first speed but at a time relative to when they are being conveyed at said slower speed and when said trailing edges are still being supported by said conveyor moving at said first speed, imbricating said sheets into a stream by positioning the oncoming ones of said sheets, which are moving at said first speed, underneath said sheets which are moving at said second speed, and stacking said sheets in a stack formed to the side of said stream opposite the side of said stream to where said sheets were positioned underneath.

7. The method of claim 6, including brushing the railing edges of said sheets upwardly in the said lifting of said sheets an while said sheets are being supported by said conveyor moving at said first speed.

8. The method of claim 7, wherein said sheets have a folded edge and including the step of gripping the folded edge of said sheets and passing said sheets at said first speed and into said stream relation with said folded edge in a leading position.

mg UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION' Patent No. 3,653,656 Dated April A, 1972 Inve fifl Anton R. Stobb It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

In Claim 5-, line 12,. after the comma, insert --said lifter means includinge raised portion affixed to said first means and being movable with said first means,

In Claim 7, line 1, change railing" to trailing-- Signed and sealed this 25th day of July 1972.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GQI'TSCHALK Attesting Officer Commissioner of Patents 

1. In a sheet stacker of the type including a conveyor for upwardly supporting and moving sheets in a stream relation, a bed in sheet-flow communication with said conveyor for receiving said sheets from said conveyor and collecting said sheets in a stacked relation, the improvement comprising said conveyor including a downstream section disposed in advance of and in sheet-flow communication with said bed for feeding said sheets toward said bed, said conveyor including an upstream section disposed in advance of said downstream section relative to the flow of said sheets for feeding said sheets to said downstream section, the two said sections being disposed in overlapping relation for transferring said sheets from said upstream section to said downstream section and in said stream relation, drive means operative on said sections for driving said sections at two different speeds and with the speed of said downstream section being slower than the speed of said upstream section to cause said sheets to overlap on said downstream section, and lifter means including a raised portion on said upstream section and operative on said sheets on said upstream section to lift said sheets upwardly relative to said upstream section to provide clearance for the oncoming ones of said sheets to move underneath said sheets already on said upstream section and thereby have said sheets overlap on said upstream section.
 2. The sheet stacker as claimed in claim 1, wherein said lifter means for overlapping said sheets includes a brush rotatably mounted above said upstream section for engaging the trailing edges of said sheets in the stream and raising said trailing edges off said upstream section for providing clearance for movement of the leading edges of said sheets underneath each respective leading one of said sheets in the stream.
 3. The sheet stacker as claimed in claim 1, wherein said conveyor includes a first section in sheet-flow communication with said upstream section, and including a drive connection operative on said first section for driving said first section at the speed oF said upstream section and with said raised portion being located along the length of said upstream section to present said raised portion adjacent the leading edges of said sheets coming onto said upstream section.
 4. The sheet stacker as claimed in claim 1, wherein said downstream section and said upstream section respectively include rotatable members disposed on a common axis, and with said rotatable member of said upstream section and said raised portion being of a combined radial extent no greater than that of said rotatable member of said downstream section for conveying the oncoming ones of said sheets underneath those of said sheets on said downstream section.
 5. A sheet stacker for a method of stacking sheets, comprising first conveyor means for conveying sheets in a stream relation and at a first speed and separated from each other, second conveyor means in sheet-flow communication with said first conveyor means for receiving said sheets therefrom and for conveying said sheets at a second speed slower than said first speed, means for driving said first conveyor means and said second conveyor means at their respective said speeds, lifter means operative on said sheets for singly lifting each of said sheets and positioning the following one of said sheets underneath each lifted one of said sheets to provide an imbricated stream of said sheets, and stacker means for stacking said sheets by stripping said sheets off said imbricated stream on the side of said imbricated stream to which said sheets were lifted.
 6. A method of imbricating and stacking sheets being conveyed in an edgewise and stream relation by a conveyor moving at a first speed and with said sheets separated from each other, comprising the steps of conveying said separated sheets at a second speed which is slower than said first speed and in a direction having a horizontal component of motion, lifting the trailing edges of said sheets at a speed according to said first speed but at a time relative to when they are being conveyed at said slower speed and when said trailing edges are still being supported by said conveyor moving at said first speed, imbricating said sheets into a stream by positioning the oncoming ones of said sheets, which are moving at said first speed, underneath said sheets which are moving at said second speed, and stacking said sheets in a stack formed to the side of said stream opposite the side of said stream to where said sheets were positioned underneath.
 7. The method of claim 6, including brushing the railing edges of said sheets upwardly in the said lifting of said sheets and while said sheets are being supported by said conveyor moving at said first speed.
 8. The method of claim 7, wherein said sheets have a folded edge and including the step of gripping the folded edge of said sheets and passing said sheets at said first speed and into said stream relation with said folded edge in a leading position. 